A cancer diagnosis, and the battle to fight the disease, can be extremely stressful. But feeling a great amount of stress, particularly over a long period of time, may make the disease worse.

Short bursts of stress, known as the fight or flight response, can be good, helping humans avoid or escape threatening or dangerous situations.But chronic stress, day after day, can harm health.

Chronic stress, harmful to health

Stress has been shown to play a role in the development of heart disease. Stress can also contribute to cancer progression, according to researcher Erica Sloan of Monash University in Melbourne, Australia.loan said chronic stress causes release of the hormone adrenaline that promotes the spread of cancer. "It allows tumors to start making growth factors that support these new freeways out of the tumor.We are also able to show that stress can increase the speed limit on these freeways, and so it can allow tumor cells to move out of the tumors at a faster rate,” said Sloan.

Image of green spheres flowing through lymph vessels of mice that are not stressed (top) or stressed (bottom) (Le et al., Nature Communications)

The freeways are lymphatic vessels near cancerous tumors that are part of the body’s immune system.The clear fluid in the vessels contains white blood cells that help detect and destroy viruses and bacteria.

Sloan’s research has shown adrenaline primes lymphatic vessels, providing easy access to the circulatory system for malignant cells to escape and spread.

In a study described in the journal Nature Communications, Sloan and colleagues showed cancer progressed more quickly in stressed mice than in unstressed rodents.

Calmness, meditation helpful

But an inexpensive drug used to lower blood pressure may calm the stress response and slow cancer spread.

Sloan pointed to a study of women with breast cancer in Italy. "And we looked at those who have been diagnosed with breast cancer who were taking these anti-hypertensive drugs and those that were not. And what we found is that those who were taking beta-blockers showed evidence of less spread of cancer into the lymphatic system and into distant tissues," she explained. "And so we are quite optimistic that this will work in patients as well.”

FILE - Allan Lokos teaching meditation at New York's Community Meditation Center, where he first introduced many of his Buddhism-inspired 'pocket practices.'

A clinical trial is now underway in Australia to see whether beta-blockers make breast cancer less aggressive.

“A diagnosis of cancer is going to be incredibly stressful. And so I guess what this suggests is that we have an opportunity not only to treat the cancer, but also by treating the patients’ well-being," she added. "We are not just making them feel good, but potentially we are also doing something to slow the spread of cancer.”

It is possible that meditation could also be used to calm a patient, reducing the spread of cancer.